CN115336961A

CN115336961A - System and method for instrument bend detection

Info

Publication number: CN115336961A
Application number: CN202210996810.1A
Authority: CN
Inventors: V·多文戴姆; T·D·苏珀尔
Original assignee: Intuitive Surgical Operations Inc
Current assignee: Intuitive Surgical Operations Inc
Priority date: 2016-09-21
Filing date: 2017-09-20
Publication date: 2022-11-15
Also published as: WO2018057633A1; US11980344B2; CN109715037A; JP7167035B2; EP3515281A1; EP3515281A4; JP2019529044A; KR20190045380A; KR102401263B1; CN109715037B; US20190239723A1

Abstract

The application is entitled "system and method for instrument bend detection". A method includes measuring a shape of a section of an elongate flexible instrument with a sensor and comparing the measured shape of the section of the elongate flexible instrument to an expected shape. The method also includes determining whether a measured shape of the section of the elongate flexible instrument differs from an expected shape by a predefined threshold.

Description

System and method for instrument bend detection

This application is a divisional application of chinese patent application 201780057175.8 (PCT/US 2017/052534) entitled "system and method for instrument bend detection" filed on 20/9/2017.

Cross Reference to Related Applications

This patent application claims priority AND benefit from the filing date of U.S. provisional patent application 62/397,426 entitled "SYSTEM AND METHODS FOR INSTRUMENTS BUCKLING DETECTION," filed on 21/9/2016, AND incorporated herein by reference in its entirety.

Technical Field

The present disclosure relates to systems and methods for navigating a medical instrument into an entry point of a patient, and more particularly to systems and methods for locating an entry point.

Background

Minimally invasive medical techniques aim to reduce the amount of tissue that is damaged during a medical procedure, thereby reducing recovery time, discomfort and harmful side effects for the patient. Such minimally invasive techniques may be performed through a natural orifice in the patient's anatomy or through one or more surgical incisions. Through these natural orifices or incisions, an operator may insert minimally invasive medical instruments (including surgical, diagnostic, therapeutic, or biopsy instruments) to reach a target tissue location. When such medical devices are inserted into the entry point, the portion of the medical device outside the entry point may be prone to bending. It would be desirable to use methods and systems that mitigate such bending in order to provide improved use of medical instruments.

Disclosure of Invention

Embodiments of the invention are summarized by the claims appended to the description.

According to some embodiments, a method includes measuring a shape of a section of an elongate flexible instrument with a sensor and comparing the measured shape of the section of the elongate flexible instrument to an expected shape. The method also includes determining whether the measured shape of the section of the elongate flexible instrument differs from the expected shape by a predefined threshold.

According to some embodiments, a method includes manipulating an elongate flexible instrument with an instrument drive mechanism and measuring a shape of a segment of the elongate flexible instrument with a sensor. The section of the elongate flexible instrument is located between the distal portion and the proximal instrument portion of the elongate flexible instrument. The method also includes determining, with a control system in communication with the sensor, whether the shape of the section of the elongate flexible instrument bends beyond a predefined threshold.

According to some embodiments, a system includes an instrument drive system, an elongated flexible instrument coupled to the instrument drive system, and a sensor associated with the elongated flexible instrument to measure a shape of the elongated flexible instrument. The system also includes a shape constraining mechanism positioned to constrain the elongate flexible instrument at a section between the instrument drive system and the distal end of the elongate flexible instrument and a control system configured to manipulate the elongate flexible instrument using the instrument drive mechanism and determine whether a section of the elongate flexible instrument within at least a portion of the shape constraining mechanism is bent beyond a predefined threshold.

According to some embodiments, a system includes a first catheter connected to a first instrument drive system, a first sensor associated with the first catheter to measure a first shape of the first catheter, and a first shape constraining mechanism positioned to constrain the first catheter at a first catheter segment between the first instrument drive system and a distal end of the first catheter. The system also includes a second catheter connected to the second instrument drive system and sized to slidably receive a length of the first catheter, and a control system configured to manipulate the first catheter using the first instrument drive mechanism and determine whether the first catheter segment within the first shape constraining mechanism is bent beyond a first predefined threshold.

According to some embodiments, a system includes an outer catheter, an inner catheter including a segment sized to extend within and slide relative to at least a portion of the outer catheter, a sensor associated with the inner catheter to measure a shape of the inner catheter, and a control system configured to determine whether the segment of the inner catheter is bent beyond a predefined threshold.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory in nature and are intended to provide an understanding of the present disclosure without limiting the scope of the disclosure. In this regard, other aspects, features and advantages of the present disclosure will be apparent to those skilled in the art from the following detailed description.

Drawings

Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying drawing figures. It is emphasized that, according to the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion. Additionally, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

Fig. 1 is a simplified diagram of a teleoperational medical system according to some embodiments.

Fig. 2A is a simplified diagram of a medical instrument system according to some embodiments.

Fig. 2B is a simplified diagram of a medical instrument with an extended medial tool according to some embodiments.

Fig. 3A and 3B are simplified diagrams of side views of a patient coordinate space including a medical instrument mounted on an insertion assembly, according to some embodiments.

Fig. 4A and 4B illustrate views of a surgical coordinate space including an elongated flexible instrument positioned within a shape constraining mechanism according to one example of the principles described herein.

FIG. 5 is a flow chart showing an illustrative method for detecting buckling of an elongated flexible instrument according to one example of the present disclosure.

Fig. 6A and 6B illustrate a shape data set for detecting bending of an elongated flexible instrument.

Fig. 7A and 7B illustrate a set of shape data having an expected boundary that may be used to detect bending of an elongated flexible instrument according to one example of principles described herein.

FIG. 8 illustrates a directional offset of an elongated flexible instrument from an insertion direction according to one example of the present disclosure.

Fig. 9 illustrates a multi-instrument system utilizing a bending mechanism according to one example of the present disclosure.

Embodiments of the present disclosure and their advantages are best understood by referring to the following detailed description. It should be understood that like reference numerals are used to identify like elements illustrated in one or more of the figures, wherein the illustrations in these figures are for the purpose of describing embodiments of the disclosure and are not intended to limit embodiments of the disclosure.

Detailed Description

In the following description, specific details describing some embodiments are set forth. Numerous specific details are set forth in order to provide a thorough understanding of the embodiments. It will be apparent, however, to one skilled in the art, that some embodiments may be practiced without some or all of these specific details. The specific embodiments disclosed herein are illustrative and not restrictive. Those skilled in the art may implement other elements that, although not specifically described herein, are within the scope and spirit of the present disclosure. In addition, to avoid unnecessary repetition, one or more features shown and described in connection with one embodiment may be incorporated into other embodiments unless specifically described otherwise or if the one or more features render the embodiments inoperative.

In some instances, well known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the embodiments.

The present disclosure describes various instruments and portions of instruments in terms of their state in three-dimensional space. As used herein, the term "position" refers to the location of an object or a portion of an object in three-dimensional space (e.g., three translational degrees of freedom along cartesian x, y, and z coordinates). As used herein, the term "orientation" refers to the rotational placement (three degrees of rotational freedom-e.g., roll, pitch, and yaw) of an object or a portion of an object. As used herein, the term "pose" refers to a position of an object or a portion of an object in at least one translational degree of freedom and an orientation of the object or a portion of the object in at least one rotational degree of freedom (up to a total of six degrees of freedom). As used herein, the term "shape" refers to a set of poses, positions, or orientations measured along an object.

Fig. 1 is a simplified diagram of a teleoperational medical system 100 according to some embodiments. In some embodiments, teleoperational medical system 100 may be suitable for use in, for example, surgery, diagnosis, therapy, or biopsy. As shown in FIG. 1, the medical system 100 generally includes a teleoperational manipulator assembly 102 for manipulating a medical instrument 104 while performing various procedures on a patient P. The teleoperational manipulator assembly 102 is mounted to or near the operating table T. Master assembly 106 allows an operator O (e.g., a surgeon, clinician, or physician as shown in fig. 1) to view the interventional site and control teleoperational manipulator assembly 102.

Master assembly 106 may be located at a user station (e.g., a physician's console) that is typically located in the same room as surgical table T, e.g., next to the surgical table where patient P is located. However, it should be understood that operator O may be located in a different room or a completely different building than patient P. The main assembly 106 typically includes one or more control devices for controlling the teleoperated manipulator assembly 102. The control device may include any number of various input devices, such as joysticks, trackballs, data gloves, trigger guns, hand-operated controllers, voice recognition devices, human motion or presence sensors, and/or the like. In order to provide the operator O with a strong sense of directly controlling the instrument 104, the control device may have the same degrees of freedom as the associated medical instrument 104. In this manner, the control device provides the operator O with a remote presentation or perception that the control device is integral with the medical instrument 104.

In some embodiments, the control device may have more or fewer degrees of freedom than the associated medical instrument 104 and still provide telepresence to the operator O. In some embodiments, the control device may optionally be movable in six degrees of freedom and may also include a manual input device for actuating an actuatable handle of the instrument (e.g., a jaw for closing a grip, applying an electrical potential to an electrode, providing a medication, and/or the like).

Teleoperated manipulator assembly 102 supports medical instrument 104 and may include one or more non-servo controlled links (e.g., one or more links that may be manually positioned and locked in place, which are commonly referred to as a set-up structure) kinematic structures and teleoperated manipulators. The teleoperational manipulator assembly 102 may optionally include a plurality of actuators or motors that drive inputs on the medical instrument 104 in response to commands from a control system (e.g., control system 112). The actuator may optionally include a drive system that, when coupled to the medical instrument 104, may advance the medical instrument 104 into a naturally or surgically created anatomical orifice. Other drive systems may move the distal end of the medical instrument 104 in multiple degrees of freedom, which may include three degrees of linear motion (e.g., linear motion along X, Y, Z cartesian axes) and three degrees of rotational motion (e.g., rotation about X, Y, Z cartesian axes). Additionally, the actuator can be used to actuate an articulatable end effector of the medical instrument 104 for grasping tissue in a jaw of the biopsy device and/or the like. Actuator position sensors, such as resolvers, encoders, potentiometers, and other mechanisms, may provide sensor data describing the rotation and orientation of the motor shaft to the medical system 100. The position sensor data may be used to determine the motion of an object manipulated by the actuator.

The teleoperational medical system 100 may include a sensor system 108, the sensor system 108 having one or more subsystems for receiving information about the instruments of the teleoperational manipulator assembly 102. Such a subsystem may include: a position/location sensor system (such as an Electromagnetic (EM) sensor system); a shape sensor system for determining a position, orientation, velocity, speed, pose, and/or shape of the distal end and/or along one or more sections of the flexible body that may comprise the medical instrument 104; and/or a visualization system for capturing images from the distal end of the medical instrument 104.

The teleoperational medical system 100 also includes a display system 110 for displaying images or representations of the surgical site and the medical instrument 104 generated by the subsystems of the sensor system 108. Display system 110 and master assembly 106 may be oriented such that operator O is able to control medical instrument 104 and master assembly 106 by way of telepresence.

In some embodiments, the medical instrument 104 may have a visualization system (discussed in more detail below) that may include a view range component that records concurrent or real-time images of the surgical site and provides the images to the operator or operator O via one or more displays of the medical system 100 (e.g., one or more displays of the display system 110). The concurrent images may be, for example, two-dimensional or three-dimensional images captured by an endoscope positioned within the surgical site. In some embodiments, the visualization system includes endoscopic components that may be integrally or removably coupled to the medical instrument 104. However, in some embodiments, a separate endoscope attached to a separate manipulator assembly may be used with the medical instrument 104 to image the surgical site. The visualization system may be implemented as hardware, firmware, software, or a combination thereof that interacts with or is otherwise executed by one or more computer processors, which may include the processors of the control system 112.

The display system 110 may also display images of the surgical site and medical instruments captured by the visualization system. In some examples, teleoperational medical system 100 may configure controls of medical instrument 104 and master assembly 106 such that the relative position of the medical instrument is similar to the relative position of the eyes and hands of operator O. In this manner, the operator O may manipulate the medical instrument 104 and hand controls as if substantially physically looking at the workspace. Being immersive means that the presentation of the image is a true perspective image simulating the perspective of the operator who is physically manipulating the medical instrument 104.

In some examples, display system 110 may present images of the surgical site recorded preoperatively or intra-operatively using image data from imaging techniques such as Computed Tomography (CT), magnetic Resonance Imaging (MRI), fluoroscopy, thermal melt printing, ultrasound, optical Coherence Tomography (OCT), thermal imaging, impedance imaging, laser imaging, nanotube X-ray imaging, and/or the like. The preoperative or intraoperative image data may be presented as two-dimensional, three-dimensional or four-dimensional (including, for example, time-based or velocity-based information) images and/or as images from a model created from a preoperative or intraoperative image data set.

In some embodiments, the display system 110 may display a virtual navigation image in which the actual location of the medical instrument 104 is registered (i.e., dynamically referenced) with a pre-operative or concurrent image/model, typically for the purpose of imaging guided surgery. This can be done: the operator O is presented with a virtual image of the internal surgical site from the perspective of the medical instrument 104. In some examples, the viewing angle may be from the tip of the medical instrument 104. An image of the tip of the medical instrument 104 and/or other graphical or alphanumeric indicators may be superimposed on the virtual image to assist the operator O in controlling the medical instrument 104. In some examples, the medical instrument 104 may not be visible in the virtual image.

In some embodiments, the display system 110 may display a virtual navigation image in which the actual positioning of the medical instrument 104 is registered with the pre-operative or concurrent image to present the operator O with a virtual image of the medical instrument 104 within the surgical site from an external perspective. An image or other graphical or alphanumeric indicator of a portion of the medical instrument 104 may be superimposed on the virtual image to assist the operator O in controlling the medical instrument 104. As described herein, a visual representation of the data point may be presented to the display system 110. For example, the measured data points, the moved data points, the registered data points, and other data points described herein may be displayed in a visual representation on the display system 110. The data points may be visually represented in the user interface by a plurality of or small dots on the display system 110 or represented as a rendered model, such as a grid or line model created based on the set of data points. In some examples, the data points may be color coded according to the data they represent. In some embodiments, the visual representation may be refreshed in the display system 110 after each processing operation has been performed to change the data point.

The teleoperational medical system 100 also includes a control system 112. The control system 112 includes at least one memory and at least one computer processor (not shown) for effecting control between the medical instrument 104, the master assembly 106, the sensor system 108 and the display system 110. The control system 112 also includes programmed instructions (e.g., a non-transitory machine-readable medium storing instructions) to implement some or all of the methods described in accordance with aspects disclosed herein, the programmed instructions comprising instructions for providing information to the display system 110. While the control system 112 is shown as a single block in the simplified schematic of fig. 1, the system may include two or more data processing circuits, with a portion of the processing optionally occurring on or near the teleoperational manipulator assembly 102, another portion of the processing occurring at the main assembly 106, and/or the like. The processor of the control system 112 may execute instructions, including instructions corresponding to the processes disclosed herein and described in more detail below. Any of a variety of centralized or distributed data processing architectures may be employed. Similarly, the programmed instructions may be implemented as separate programs or subroutines, or they may be integrated into various other aspects of the remote operating system described herein. In one embodiment, the control system 112 supports wireless communication protocols such as Bluetooth, irDA, homeRF, IEEE 802.11, DECT, and wireless telemetry.

In some embodiments, the control system 112 may receive force and/or torque feedback from the medical instrument 104. In response to this feedback, the control system 112 may send a signal to the master assembly 106. In some examples, the control system 112 may send a signal instructing one or more actuators of the teleoperational manipulator assembly 102 to move the medical instrument 104. The medical instrument 104 may extend to an internal surgical site within the body of the patient P via an opening in the body of the patient P. Any suitable conventional and/or dedicated actuator may be used. In some examples, the one or more actuators may be separate from or integrated with the teleoperated manipulator assembly 102. In some embodiments, the one or more actuators and teleoperated manipulator assemblies 102 are provided as part of a teleoperated cart positioned near the patient P and the surgical table T.

The control system 112 may optionally further include a virtual visualization system to provide navigational assistance to the operator O in controlling the medical instrument system 104 during image-guided surgery. The virtual navigation using the virtual visualization system is based on a reference to a pre-operative or intra-operative data set of the acquired anatomical passageways. The virtual visualization system processes images of the surgical site imaged using imaging techniques (e.g., computed Tomography (CT), magnetic Resonance Imaging (MRI), fluoroscopy, thermography, ultrasound, optical Coherence Tomography (OCT), thermal imaging, impedance imaging, laser imaging, nanotube X-ray imaging, and/or the like). Software, which may be used in conjunction with manual input, is used to convert the recorded images into a segmented two-dimensional or three-dimensional composite representation of part or the entire anatomical organ or anatomical region. The image data set is associated with a composite representation. The composite representation and image data set describe the various locations and shapes of the channels and their connectivity. The images used to generate the composite representation may be pre-or intra-operatively recorded during a clinical procedure. In some embodiments, the virtual visualization system may use a standard representation (i.e., not patient-specific) or a mixture of standard representation and patient-specific data. The composite representation and any virtual images produced by the composite representation may represent a static pose of the deformable anatomical region during one or more motion phases (e.g., during an inhalation/exhalation cycle of the lung).

During the virtual navigation procedure, the sensor system 108 may be used to calculate an approximate location of the medical instrument 104 relative to the anatomy of the patient P. This positioning can be used to generate a macroscopic (external) tracking image of the anatomy of the patient P and a virtual internal image of the anatomy of the patient P. The system may implement one or more Electromagnetic (EM), fiber optic, and/or other sensors to register and display medical implementations with known preoperatively recorded surgical images, such as those from a virtual visualization system. For example, U.S. patent application No.13/107,562 (filed on 13.5.2011) (disclosing "Medical System Providing Dynamic Registration of a Model of an anatomical Structure for Image-Guided Surgery)" which is incorporated herein by reference in its entirety, discloses one such System.

The teleoperational medical system 100 may also include optional operational and support systems (not shown), such as an illumination system, a steering control system, an irrigation system, and/or a suction system. In some embodiments, teleoperational medical system 100 may include more than one teleoperational manipulator assembly and/or more than one master assembly. The exact number of teleoperational manipulator assemblies will depend on the surgical procedure and the space constraints within the operating room, among other factors. The main assemblies 106 may be juxtaposed or they may be positioned in separate locations. The multiple master assemblies allow more than one operator to control one or more teleoperated manipulator assemblies in various combinations.

Fig. 2A is a simplified diagram of a medical instrument system 200 according to some embodiments. In some embodiments, the medical instrument system 200 may be used as a medical instrument 104 in an image-guided medical procedure performed with the teleoperational medical system 100. In some examples, the medical instrument system 200 may be used for non-teleoperated exploratory procedures or procedures involving traditional manually operated medical instruments (e.g., endoscopy). Alternatively, the medical instrument system 200 can be used to collect (i.e., measure) a set of data points corresponding to locations within an anatomical passageway of a patient, such as patient P.

The medical instrument system 200 includes an elongate device 202 (such as a flexible catheter) coupled to a drive unit 204. The elongate device 202 includes a flexible body 216 having a proximal end 217 and a distal or tip portion 218. In some embodiments, the flexible body 216 has an outer diameter of about 3 mm. Other flexible body outer diameters may be larger or smaller.

The medical instrument system 200 also includes a tracking system 230 for determining a position, orientation, velocity, speed, pose, and/or shape of the distal end 218 and/or along one or more sections 224 of the flexible body 216 using one or more sensors and/or imaging devices as described in further detail below. The entire length of the flexible body 216 between the distal end 218 and the proximal end 217 may be effectively divided into sections 224. The system 230 is tracked if the medical instrument system 200 is consistent with the medical instrument 104 of the teleoperational medical system 100. The tracking system 230 may optionally be implemented as hardware, firmware, software, or a combination thereof that interacts with or is otherwise executed by one or more computer processors, which may include the processors of the control system 112 in fig. 1.

The tracking system 230 may optionally track one or more of the distal end 218 and/or the segment 224 using the shape sensor 222. The shape sensor 222 may optionally include an optical fiber aligned with the flexible body 216 (e.g., disposed within an internal passage (not shown) or mounted externally). In one embodiment, the optical fiber has a diameter of about 200 μm. In other embodiments, the dimensions may be larger or smaller. The optical fibers of the shape sensor 222 form a fiber optic bend sensor for determining the shape of the flexible body 216. In one alternative, an optical fiber including a Fiber Bragg Grating (FBG) is used to provide strain measurements of the structure in one or more dimensions. Various systems and methods for monitoring the shape and relative position of an Optical Fiber in three dimensions are described in U.S. patent application Ser. No.11/180,389 (filed on 13/7/2005) (disclosing "Fiber optic position and shape sensing devices and associated methods)") and U.S. patent application Ser. No.12/047,056 (filed on 16/7/2004) (disclosing "Fiber-optic shape and relative position sensing)") and U.S. patent No.6,389,187 (filed on 17/6/1998) (disclosing "Optical Fiber Bend Sensor)", the disclosures of which are incorporated herein by reference in their entirety. The sensor in some embodiments may employ other suitable strain sensing techniques, such as rayleigh scattering, raman scattering, brillouin scattering, and fluorescence scattering. In some embodiments, the shape of the elongated device may be determined using other techniques. For example, a history of the pose of the distal end of the flexible body 216 may be used to reconstruct the shape of the flexible body 216 over a time interval. In some embodiments, the tracking system 230 may alternatively and/or additionally track the distal end 218 using the position sensor system 220. The position sensor system 220 may be a component of an EM sensor system, wherein the position sensor system 220 includes one or more conductive coils that may be subjected to an externally generated electromagnetic field. Each coil of the EM sensor system 220 then generates an induced electrical signal having characteristics that depend on the position and orientation of the coil relative to the externally generated electromagnetic field. In some embodiments, the position sensor system 220 may be configured and positioned to measure six degrees of freedom, e.g., three position coordinates X, Y, Z and three orientation angles indicating pitch, yaw, and roll of the base point, or five degrees of freedom, e.g., three position coordinates X, Y, Z and two orientation angles indicating pitch, yaw of the base point. A further description of a position sensor System is provided in U.S. Pat. No.6,380,732 (filed 11.8.1999) (disclosing "Six-Degree-of-Freedom Tracking System with Passive transducers on the Tracked Object" with the Six-Degree-of-Freedom Tracking System ") which is incorporated herein by reference in its entirety.

In some embodiments, the tracking system 230 may alternatively and/or additionally rely on historical posture, position, or orientation data stored for known points of the instrument system along a cycle of alternating motion (e.g., breathing). This stored data may be used to form shape information about the flexible body 216. In some examples, a series of position sensors (not shown), such as Electromagnetic (EM) sensors similar to the sensors in position sensor 220, may be positioned along flexible body 216 and then used for shape sensing. In some examples, a history of data collected during the procedure from one or more of these sensors may be used to represent the shape of the elongated device 202, particularly if the anatomical passageway is generally static.

The flexible body 216 includes a channel 221, the channel 221 being sized and shaped to receive the medical instrument 226. Fig. 2B is a simplified diagram of the flexible body 216 with the medical instrument 226 extended according to some embodiments. In some embodiments, the medical instrument 226 may be used for procedures such as surgery, biopsy, ablation, illumination, irrigation, or suction. The medical device 226 may be deployed through the channel 221 of the flexible body 216 and used at a target location within the anatomy. The medical instrument 226 may include, for example, an image capture probe, a biopsy instrument, a laser ablation fiber, and/or other surgical, diagnostic, or therapeutic tools. The medical tool may include an end effector having a single working member, such as a scalpel, a blunt blade, an optical fiber, an electrode, and/or the like. Other end effectors may include, for example, forceps, graspers, scissors, clip appliers, and/or the like. Other end effectors may also include electrically activated end effectors such as electrosurgical electrodes, transducers, sensors, and/or the like. In various embodiments, the medical instrument 226 is a biopsy instrument that may be used to remove sample tissue or cell samples from a target anatomical location. The medical device 226 may also be used with an image capture probe within the flexible body 216. In various embodiments, the medical instrument 226 may be an image capture probe that includes a distal portion having a stereoscopic or monoscopic camera at or near the distal end 218 of the flexible body 216 for capturing images (including video images) processed by a visualization system 231 for display and/or providing to a tracking system 230 to support tracking of the distal end 218 and/or one or more sections 224. The image capture probe may include a cable coupled to the camera for transmitting captured image data. In some examples, the image capture instrument may be a fiber optic bundle, such as a fiberscope, coupled to the visualization system 231. The image capture instrument may be single-spectral or multi-spectral, for example capturing image data in one or more of the visible, infrared, and/or ultraviolet spectra. Alternatively, the medical instrument 226 itself may be an image capture probe. The medical instrument 226 may be advanced from the opening of the channel 221 to perform a procedure, and then retracted into the channel when the procedure is complete. The medical instrument 226 may be removed from the proximal end 217 of the flexible body 216 or from another optional instrument port (not shown) along the flexible body 216.

The medical instrument 226 may additionally house cables, linkages or other actuation controls (not shown) extending between its proximal and distal ends to controllably bend the distal end of the medical instrument 226. Steerable Instruments are described in detail in U.S. Pat. No.7,316,681 (filed on 4/10/2005) (disclosing "Articulated Surgical Instrument for Performing Minimally Invasive Surgery with Enhanced Dexterity and Sensitivity)" and U.S. Pat. No.12/286,644 (filed 30/9/2008) (disclosing "Passive Loading and Capstation Drive for Surgical Instruments" which are incorporated herein by reference in their entirety).

The flexible body 216 may also house cables, linkages, or other steering controls (not shown) that extend between the drive unit 204 and the distal end 218 to controllably bend the distal end 218, for example, as shown by the dashed line depiction 219 of the distal end 218. In some examples, at least four cables are used to provide independent "up and down" steering to control pitch of distal end 218 and "left and right" steering to control yaw of distal end 281. Steerable elongated devices are described in detail in U.S. patent application No.13/274,208 (filed on 14/10/2011), which discloses a Catheter with Removable Vision Probe, incorporated herein by reference in its entirety. In embodiments where the medical instrument system 200 is actuated by a teleoperational assembly, the drive unit 204 may include a drive input that is removably coupled to and receives power from a drive element (e.g., an actuator) of the teleoperational assembly. In some embodiments, the medical instrument system 200 may include gripping features, manual actuators, or other components for manually controlling the motion of the medical instrument system 200. The elongate device 202 may be steerable or, alternatively, the system may be non-steerable and without an integrated mechanism for the operator to control the bending of the distal end 218. In some examples, one or more lumens through which medical instruments may be deployed and used at a target surgical site are defined in the wall of the flexible body 216.

In some embodiments, the medical instrument system 200 may include a flexible bronchial instrument, such as a bronchoscope or bronchial catheter, for examination, diagnosis, biopsy, or treatment of the lung. The medical device system 200 is also suitable for navigation and treatment of other tissues through natural or surgically created connected passageways in any of a variety of anatomical systems, including the colon, intestines, kidneys and renal calyces, brain, heart, circulatory systems including the vasculature, and/or the like.

Information from the tracking system 230 may be sent to a navigation system 232 where it is combined with information from a visualization system 231 and/or a pre-operatively obtained model to provide real-time location information to the operator or other operators in the navigation system 232. In some examples, the real-time location information may be displayed on the display system 110 of fig. 1 for controlling the medical instrument system 200. In some examples, the control system 112 of fig. 1 may utilize the position information as feedback for positioning the medical instrument system 200. Various systems for registering and displaying surgical instruments and surgical images using fiber optic sensors are provided in U.S. patent application No.13/107,562 (filed on 13.5.2011) (disclosing "Medical System Providing Dynamic Registration of a Model of an anatomical Structure for Image-Guided Surgery)", which is incorporated herein by reference in its entirety.

In some examples, the medical instrument system 200 may be remotely operated within the medical system 100 of fig. 1. In some embodiments, the teleoperational manipulator assembly 102 of fig. 1 may be replaced by direct operator controls. In some examples, the direct operator controls may include various handles and operator interfaces for handheld operation of the instrument.

Fig. 3A and 3B are simplified diagrams of side views of a patient coordinate space including a medical instrument mounted on an insertion assembly according to some embodiments. As shown in fig. 3A and 3B, surgical environment 300 includes a patient P positioned on a platform T. Patient P may be stationary in the surgical environment in the sense that the overall motion of the patient is limited by sedation, binding, and/or other means. The cyclic anatomical motion, including the breathing and cardiac motion of the patient P, may continue unless the patient is required to hold his or her breath to temporarily halt the breathing motion. Thus, in some embodiments, data may be collected at a particular stage of respiration and labeled and identified with that stage. In some embodiments, the stage at which data is collected may be inferred from the physiological information collected by patient P. In surgical environment 300, a point collection instrument 304 is coupled to an instrument carriage 306. In some embodiments, the point collection instrument 304 may use EM sensors, shape sensors, and/or other sensor modalities. Instrument carriage 306 is mounted to an insertion station 308 secured within surgical environment 300. Alternatively, the insertion stage 308 may be movable, but have a known position within the surgical environment 300 (e.g., via a tracking sensor or other tracking device). Instrument carriage 306 may be a component of a teleoperated manipulator assembly (e.g., teleoperated manipulator assembly 102) that is coupled to point collection instrument 304 to control insertion motion (i.e., motion along the a-axis) of distal end 318 of elongate device 310 and, optionally, to control motion of distal end 318 of elongate device 310 in multiple directions, including yaw, pitch, and roll. Instrument carriage 306 or insertion station 308 may include an actuator, such as a servo motor (not shown), that controls movement of instrument carriage 306 along insertion station 308.

The elongate device 310 is coupled to an instrument body 312. The instrument body 312 is coupled and fixed relative to the instrument carriage 306. In some embodiments, the fiber optic shape sensor 314 is fixed at a proximal point 316 on the instrument body 312. In some embodiments, the proximal point 316 of the fiber optic shape sensor 314 may move with the instrument body 312, but the location of the proximal point 316 may be known (e.g., via a tracking sensor or other tracking device). The shape sensor 314 measures the shape from a proximal point 316 to another point, such as a distal end 318 of the elongate device 310. The point collection instrument 304 may be substantially similar to the medical instrument system 200.

The position measurement device 320 provides information about the position of the instrument body 312 as the instrument body 312 is moved along the insertion axis a on the insertion station 308. Position measurement device 320 may include a rotary transformer, encoder, potentiometer, and/or other sensor that determines the rotation and/or orientation of an actuator that controls the movement of instrument carriage 306 and thus instrument body 312. In some embodiments, the insertion station 308 is linear. In some embodiments, the insertion station 308 may be curved or have a combination of curved and linear segments.

Fig. 3A shows the instrument body 312 and instrument carriage 306 in a retracted position along the insertion station 308. In the retracted position, the proximal point 316 is located at a position L0 on the axis a. In this position along the insertion stage 308, one component of the proximal point 316 location may be set to zero and/or another reference value to provide a fiducial reference to describe the position of the instrument carriage 306, and thus the proximal point 316, on the insertion stage 308. With the instrument body 312 and instrument carriage 306 in this retracted position, the distal end 318 of the elongate device 310 may be positioned just within the access aperture of the patient P. Also at this position, the position measurement device 320 may be set to zero and/or another reference value (e.g., I = 0). The collapsible shape restraint device 272 supports the elongate device 310 between the instrument body 312 and the access orifice of the patient P. The collapsible shape restraining device 272 restrains the flexible elongate device 310 to the narrow channel defined by the shape restraining device and supports the instrument body against buckling as it is pushed forward (distally) along axis a. Consistent with embodiments of the present disclosure, a device may be considered bent if it exhibits a non-linear shape, particularly a non-linear shape that exceeds a predefined threshold. The predefined threshold need not be associated with an immediate mechanical failure, but may be a shape associated with reduced accuracy, reduced control, predicted failure, or other suboptimal performance. The predefined threshold may depend on another measure, such as insertion distance, friction detection, obstacle detection, distal curvature detection, or planned navigation route.

In fig. 3B, instrument body 312 and instrument carriage 306 have been advanced along the linear track of insertion station 308, and distal end 318 of elongated device 310 has been advanced into patient P. In this advanced position, the proximal point 316 is at position L1 on axis a. In some examples, encoders and/or other position data from one or more actuators controlling movement of instrument carriage 306 along insertion station 308 and/or one or more position sensors associated with instrument carriage 306 and/or insertion station 308 are used to determine position Lx of proximal point 316 relative to position L0. In some examples, the location Lx may also be used as an indication of the distance or depth of insertion of the distal end 318 of the elongate device 310 into a channel of the anatomy of the patient P.

The collapsible shape restraining device 272 helps prevent the flexible elongate device 310 from buckling as the instrument body 312 is advanced toward the patient access orifice. The length of the flexible elongate device 310 contained within the device 272 has the desired straight linear shape. The shape of the flexible elongate device 310 within the device may be measured by a shape sensor 314. If the measured shape of the shape sensor 314 exhibits a non-linear shape or bend that exceeds a predefined threshold, an error may be reported, indicating that the shape constraining device failed to maintain the intended configuration of the flexible elongate instrument, and thus failed to maintain the intended configuration of the shape sensor.

Fig. 4A and 4B illustrate views of a surgical coordinate space 400, the surgical coordinate space 400 including a flexible elongate instrument 404 (e.g., devices 310, 202) positioned within a shape constraining device 408. As previously mentioned, the flexible elongate instrument may be a catheter. The shape constraining device 408 may contract when the catheter is inserted into the access port 406 and expand when the catheter is retracted from the access port. The catheter 404 is coupled to the instrument body 402. The catheter 304 also includes a shape sensor 412. Fig. 4A shows the shape-constraining device 408 in an expanded position, while fig. 4B shows the shape-constraining device in a contracted position.

The shape sensor 412 generates shape data that can be used to determine the shape of the catheter 404. The shape data may be used to determine the pose of the distal end 407 of the catheter 404 within the surgical coordinate space 400. For example, if the location of a particular portion of the catheter 404 is known or tracked in the surgical coordinate space 400 (i.e., the base 403 of the catheter 404), the shape data may be used to determine the location of any point along the catheter 304 in the surgical coordinate space 400. Various shape sensing systems may be used alternatively or in combination to generate shape data.

In one example, the shape sensor 412 is a fiber optic shape sensor. Such a shape sensor may include one or more fiber optic cables extending along the length of the catheter 404. The fiber optic shape sensor may include one or more optical cores. In some cases, the fiber optic shape sensor may include one or more optical fibers, each having one or more optical cores. As described above, the core may include a fiber bragg grating to provide strain measurements in one or more dimensions. In other alternatives, sensors employing other strain sensing technologies may be suitable. In one example, the fiber optic shape sensor utilizes an interrogation system (not shown) positioned proximal to the base 403 of the catheter 404. In operation, the interrogation system generates light and detects the returned light to determine the current shape of the optical fiber shape sensor. The interrogation system may then create data representative of the detected light. This data may be analyzed to determine the location and orientation of any point along the length of the catheter 404. Because the base 403, which acts as a reference fixture, may have a fixed, known, or tracked position in the surgical coordinate space 400, the position and orientation of any point along the catheter 404 relative to the surgical coordinate space may be determined from the sensor data.

In one example, the shape sensor 412 includes a plurality of Electromagnetic (EM) sensors along the length of the catheter 404. As described above, the EM sensor may include one or more conductive coils that may be subjected to an electromagnetic field generated by an EM transmitter (not shown). Each coil of the EM sensor then generates an induced electrical signal having characteristics that depend on the position and orientation of the coil relative to the electromagnetic field generated by the EM transmitter. Thus, the EM sensor may measure six degrees of freedom, e.g., three position coordinates X, Y, Z and three orientation angles indicating pitch, yaw and roll of the base point, or five degrees of freedom, e.g., three position coordinates X, Y, Z and two orientation angles indicating pitch and yaw of the base point.

In one example, the shape sensor 412 includes an optical marker for analyzing imaging data obtained by a video camera system. For example, a plurality of video cameras or still cameras may be directed at a portion 410 of the catheter 404 outside of the entry port 406. The camera may be stereoscopic in order to obtain data representing the position of the catheter 404 within the surgical coordinate space 400. The optical markers may include varying colors, reflectivity, texture, or other features, which may allow for more efficient analysis of imaging data generated by the video camera.

The instrument body 402 may be substantially similar to the body 312 and is connected to an instrument carriage 416, which instrument carriage 416 may be part of a teleoperated manipulator assembly (e.g., assembly 102) that may be moved along an insertion station 418 within a surgical coordinate space to insert and retract the catheter 404 from the access port 406. The teleoperational manipulator assembly may be part of a teleoperational system (e.g., system 100) that includes a control system 414 having a processor and memory and software (machine-readable instructions) to operate the catheter 404. For example, the control system may operate motors that control movement of instrument drive mechanism 402 as well as motors that control wires and other mechanisms that steer the distal end of catheter 404. The control system 414 may also process data obtained from the shape sensor 412 to determine the shape of the catheter 404 in real time.

The catheter 404 may be inserted into a natural orifice of a patient or a surgically created incision. Where the orifice is the patient's mouth, the access port 406 may be, for example, an endotracheal tube. Where the port is a surgically created incision, the access port 406 may be, for example, a trocar cannula.

The shape restraining device 408 is positioned between the instrument body 402 and the access port 406. The shape restraining device 408 may limit bending when the catheter 404 is inserted into the access port 406. Various types of shape-constraining devices may be used in accordance with the principles described herein. For example, the shape restraint device 408 may include a series of linkages as described in U.S. provisional patent application 61/823,666 entitled "Guide Apparatus for Delivery of a Flexible Instrument and Methods of Use" filed on 2013, 5, 15, which is hereby incorporated by reference in its entirety. In some examples, shape restraining Device 408 may include a series Of retaining members And a series Of support members, as described in U.S. provisional patent application No.62/029,917, entitled "Guide Apparatus For Delivery Of Flexible instruments And Methods Of Use," filed on 28.7.2014 And U.S. provisional patent application No.62/359,957, filed on 8.7.2016, entitled "Guide Apparatus For Delivery Of elongated devices And Methods Of Use," filed on 28.7.7.4, which are hereby incorporated by reference in their entirety.

The shape constraining device 408 generally helps prevent kinking, sagging, or other non-linear configurations of the conduit 404, however, to prevent friction formation between the conduit and the device, the device may be sized slightly larger (e.g., 2-10 millimeters) than the conduit. Due to the size difference, in the advanced position, the conduit 404 may not maintain an accurate linear shape, and thus the portion of the conduit 404 outside of the entry port 406 may be longer than the length D1. Shape sensor data from sensor 412 may be used to determine the shape of catheter 404 over length D1. If the determined shape exceeds the expected (typically linear) shape by a threshold, the system 414 may perform an action such as a user alert, a feedback signal to stop further advancement, or an applied force to correct the shape.

The control system 414 may be used to determine a minimum length of the portion 410 of the conduit 404 outside of the access port 406. As shown in FIG. 4B, the length of the portion 410 becomes smaller when the catheter 404 is inserted into the access port 406. Can use eachA technique determines the minimum length of portion 410 at any given time during operation of catheter 404. In one example, data from an insertion sensor (e.g., an encoder) associated with a motor of instrument carriage 416 driving catheter 404 can be used to determine the minimum length of portion 410. For example, in the retracted position, the proximal point 420 on the instrument body 402 is at a location L on the axis A ₀ To (3). In this position along the insertion stage 418, one component of the proximal point 420 location may be set to zero and/or another reference value to provide a fiducial reference to describe the position of the instrument carriage 416, and thus the proximal point 420, on the insertion stage 418. With the instrument body 402 and instrument carriage 416 in this retracted position, the distal end 407 of the flexible elongate instrument 404 may be positioned just within the access port 406. In the retracted position, the minimum length of the portion 410 outside of the access port 406 is length D1. If instrument 404 is substantially unbent, the minimum length of portion 410 may be approximately the same as the minimum length of portion 410. Also at this position, the insertion sensor may be set to an initial value (e.g., zero and/or another reference value). In fig. 4B, the instrument body 402 and instrument carriage 416 have been advanced along the insertion station 418, and the distal end of the flexible elongate instrument 404 has been advanced through the access port 406. In this advanced position, the proximal point 420 is located at a position L on the A-axis ₁ To (3). Data indication L from insertion sensor ₀ And L ₁ The distance between them. More specifically, data from the encoder sensor may indicate a change in motor state. The state of the motor may include the current rotational position of the motor and the number of turns the motor has made from the reference state. The minimum length of the portion 410 outside of the access port 406 is the length D2, which is approximately the length D1 minus L ₀ And L ₁ The distance advanced therebetween. If the portion 410 outside of the access port 406 is bent, the actual length of the portion 410 may exceed the length D2.

The control system 414 may analyze the shape of the catheter 404 during catheter operation. For example, the control system analyzes data from the shape sensor 412 to determine the current shape of the catheter 404. The control system 414 then compares the shape data received from the shape sensor to the expected shape. Various techniques may be used to define the desired shape. For example, as will be described in further detail below, comparing the shape data to an expected shape may include determining whether a current shape of the catheter 404 exceeds an expected boundary. Comparing the shape data to the expected shape may also include determining that a portion of the catheter has been offset from the axis a by a predefined distance. Comparing the shape data to the expected shape may also include determining a directional movement of the catheter 404 in a direction orthogonal to the insertion direction.

If the control system 414 determines that the current shape differs from the expected shape by a predetermined amount, the control system may trigger a bend-mitigating action. In one example, the kink mitigation action includes reporting a warning or error message to an operator of the catheter 404. In one example, the bend mitigating action includes transitioning the catheter control system to a safe state. The safe state is a state in which further movement of the catheter is inhibited. In some examples, the bend-mitigating action may include indicating to the user that a precise portion of the catheter 404 has exceeded an intended shape. In some examples, the bend mitigating action may include automatically retracting or adjusting the position of the catheter 404 until the current shape of the catheter 404 returns to a state closer to the desired shape. In one example, the bend mitigating action may include modifying a shape of the shape constraining device to reduce the measured bend. For example, the shape-constraining device may be controlled to deform in a direction opposite to the measured bend to return the catheter to the desired shape. Alternatively, if the catheter bends due to friction with the restriction device, the restriction device may be rotated about its longitudinal axis to overcome the static friction.

FIG. 5 is a flow chart showing an illustrative method 450 for detecting bending of an elongated flexible instrument. The method 450 is illustrated in FIG. 5 as a set of operations or processes 452-456. Not all of the illustrated processes 452-456 may be performed in all embodiments of the method 450. Additionally, one or more processes not explicitly shown in FIG. 5 may be included before, after, between, or as part of processes 452-456. In some embodiments, one or more of the processes may be implemented, at least in part, in the form of executable code stored on a non-transitory tangible machine-readable medium, which when executed by one or more processors (e.g., a processor of control system 112 or 414) may cause the one or more processors to perform one or more of the processes.

According to the present example, the method 450 includes a step 452 for measuring a shape of a segment of the elongate flexible instrument between an anatomical access passage (e.g., the access port 406 at a patient's mouth or a cannula at a surgically created opening) and a proximal instrument portion (e.g., the instrument body 402) with a sensor. The sensor may be, for example, a fiber optic shape sensor, a series of EM sensors, or an imaging sensor. The method 450 also includes a step 454 for comparing the measured shape of the section of the elongate flexible instrument with an expected shape. The desired shape may be a line through a shape constraining device (e.g., an anti-buckling mechanism 408 placed between the anatomic access passage and the proximal instrument portion) corresponding to a reference axis (e.g., a central axis or a base axis). Alternatively, the expected shape may be a shape having a predetermined cumulative deviation from an axis (e.g., a central axis or a base axis). Alternatively, the intended shape may be any shape that fits within the predefined volume. Alternatively, the desired shape may be a shape in which the distal end is a desired distance from the proximal end. The method 450 also includes a step 456 for determining whether the measured shape of the section of the elongate flexible instrument differs from the expected shape by a predefined threshold. Optionally, the method may further comprise triggering a mitigating action, such as providing an alert to an operator, applying a corrective force via a remote operating system, entering a safe state, or providing instructions to a user for a corrective action.

Fig. 6A illustrates shape data 500 obtained from a shape sensor (such as sensor 412) within a section of a flexible instrument between an access port and a proximal instrument body. In one example, the segment may be constrained by a shape constraining device 408. Axis 502 is the desired shape of the segment. In various examples, the expected shape 502 may represent a central axis through the shape constraint device 408 or a base axis along the gravitational bottom of the shape constraint device. The predefined threshold 504 is set at a distance 510 from the expected shape 502 based on the consistency of the expected shape required to achieve the desired accuracy of the insertion movement. The threshold may be constant along the length of the shape or vary depending on the amount of deviation expected at different points along the expected shape. In this example, the shape data 500 has a deviation 506 that exceeds a predefined threshold 504. Thus, the deviation 506 will trigger a mitigation action. In this example, the shape data 500 also has

deviations

508, 512, each

deviation

508, 512 being less than the predefined threshold 504. Neither bias 508 nor bias 512 alone triggers mitigation actions. In one example, the cumulative size of the

deviations

508 and 512 may exceed the predefined threshold 504. The accumulated deviation may trigger a mitigation action.

The predefined threshold may variably depend on measurements or on known or detected conditions. For example, when the catheter experiences friction within the anatomical passageway due to an obstructed or tortuous path, the catheter may be expected to bend within the shape constraining device. In such a case, the predefined threshold may be expanded. For example, when high input forces are measured with sensors or reference insertion motor currents, the threshold may be increased. For example, the threshold may be increased when the distal end of the catheter has a sufficiently curved shape within the patient's anatomy. For example, the threshold may be increased when the predicted planned navigation path is tortuous.

In some examples, if one deviation exceeds another by a predetermined value, a kink mitigation action is triggered. In one example, if the deviation 506 is greater than any

other deviation

508, 512 by a predetermined value, a buckling mitigation action is triggered. In some examples, if a particular deviation 506 exceeds the more distal deviation 508 or the deviation 512 by a predetermined value, a bend-mitigating action is triggered.

FIG. 6B illustrates an alternative technique for determining whether a measured shape of a segment of a flexible instrument differs from an expected shape measurement. As previously described, an encoder or other position sensor may be used to determine the distance (i.e., L) the proximal instrument body 402 is advanced _O And L ₁ The distance therebetween). In this example, shape data 550 is obtained from shape sensor 412. The proximal end 552 of the shape data 550 may correspond to a shape of a rectangle relative to a rectangleA fixed point of the proximal instrument body 402 (e.g., point 420 or catheter end 403). The distal end 554 of the shape data 550 may correspond to the distal end 407 of the catheter or the distal end of the portion 410 of the catheter 404 outside of the access port 406. The distal end 554 of the shape data 550 may be determined by a shape perturbation caused by the access port 406, a temperature change at the access port 406, or other indicator that a catheter has entered the access port. If the linear distance D3 between the data points 552 and 554 is less than L _O And L ₁ May indicate that the catheter 404 has experienced a bend. If the distance D3 exceeds L _O And L ₁ A predefined threshold value of the distance between, a mitigating action may be triggered, for example to alert the user of the bend, or to correct the bend.

Fig. 7A and 7B illustrate an expected boundary 602 that may be used to detect bending of an elongated flexible instrument 604 (e.g., instrument 404). The desired shape of the method 450 may be any shape that fits within the three-dimensional volume defined by the boundary 602. In one example, the expected boundary 602 defines a volume within the surgical coordinate space 400 that corresponds to the volume defined by the shape constraining device 408. The volume may have a substantially tubular shape. The tubular shape may be substantially straight or arcuate. In some implementations, the volume defined by the expected boundary 602 may substantially match the volume defined by the shape constraining device 408. In some embodiments, the volume defined by the intended boundary 602 may be scaled to a slightly larger or smaller volume than the volume defined by the shape constraining device 408. An expected boundary 602 may be defined relative to an axis 605 along which an elongated flexible instrument from which the shape data 504 is obtained is expected to be inserted. The expected boundary 602 represents a predefined threshold that, if exceeded by the shape data 604, results in a mitigation action being triggered.

In some examples, the expected boundary 602 may correspond to an anatomical lumen. For example, various medical imaging techniques (such as CT scans) may be used to map the anatomy of a patient. When the flexible instrument is inserted into the patient's anatomy, the expected boundary 602 may be defined based on the geometry of the anatomical lumen, where there is currently a designated portion of the flexible instrument from which the shape data 404 is obtained.

Fig. 7A illustrates an example of shape data 604 remaining within the expected boundary 602. Although the shape data 604 is shown as having a slight inflection 603, the inflection does not exceed a predefined threshold defined by the expected boundary 602. However, fig. 7B shows shape data 606 that is shaped such that a portion 608 of the shape exceeds the expected boundary 602. In this case, the control system (e.g., control system 414) may trigger the mitigation action. By comparing shape data from a shape sensor (e.g., sensor 412) to an expected boundary 602 defined relative to an insertion axis through the shape constraining mechanism, the control system may determine that a portion 608 of the shape 604 exceeds the expected boundary 602.

Fig. 8 illustrates a directional deviation of the elongated flexible instrument 652 from the insertion direction 658 (e.g., along axis a) in order to detect bending. In particular, the control system may analyze the shape sensor data in real time to determine whether a particular portion is moving in a direction substantially orthogonal to the insertion direction 658. Fig. 8 shows a portion 654 of an instrument 652 being moved in a first direction 660 substantially orthogonal to an insertion direction 658. In addition, portion 656 of instrument 652 is moving in a second direction 662 that is opposite the first direction and substantially orthogonal to insertion direction 658. If a particular portion moves a predetermined distance or a predetermined period of time in a

direction

660, 662 orthogonal to the insertion direction 658, a mitigating action is triggered. In this example, portion 654 may exceed a predetermined distance or time period while portion 656 does not exceed the predetermined distance or time period. Mitigation actions may additionally or alternatively be triggered if the local curvature (e.g., minimum bend radius) or cumulative curvature (e.g., total bend angle) of the shape in the shape constraining device exceeds a particular threshold.

Fig. 9 illustrates a multiple instrument system 701 that utilizes a shape constraining device between multiple instruments and between an instrument drive mechanism and an access port. The medical instrument system 701 (e.g., instruments 104, 200) includes an outer catheter 728, an inner catheter 726, and a medical tool 724. According to the present example, each medical instrument is connected to a

teleoperational manipulator assembly

702, 712, 718 (e.g., manipulator assembly 102).

Manipulator assembly 702 includes a base 704a, a moving arm assembly 709a (which includes a set of links 706a, a set of joints 708 a), and an end mechanism 710. The joint 708a may include a motor or other actuator to drive the movement of the arm 709a in one or more degrees of freedom. Although this example shows three links 706a coupled by two joints 708a, other examples may have other numbers of links 706 and joints 708. In some examples, the link may be a telescopic link that is capable of extending a predetermined distance. The links are pivotable about joints to move the end mechanisms to desired positions within a surgical coordinate system. Some joints may allow rotation in only one plane. Other joints may allow rotation in multiple planes.

The combination of the link 706a and the joint 708a can provide movement of the end mechanism 710 in six degrees of freedom, which can include three degrees of linear motion (e.g., linear motion along X, Y, Z cartesian axes) and three degrees of rotational motion (e.g., rotation about X, Y, Z cartesian axes). The arm 709a may include wiring, circuitry, and other electronics to communicate power and control signals from the control system 703 (e.g., the control system 112) to the actuators and the instruments and instrument end effectors coupled to the end mechanism 710. Actuator position sensors (e.g., resolvers, encoders, potentiometers, and other mechanisms) may provide sensor data describing the rotation and orientation of the motor shaft to the control system. The position sensor data may be used to determine the motion of an object manipulated by the motor. For example, a joint may have a sensor that can determine the rotational position of the joint or determine the angle at which two links connecting the joint are currently positioned. Additionally, if the link is extendable, such link may include a sensor to determine the distance the link is currently extending. In this manner, the position of the end mechanism relative to the base can be determined based on data from such sensors. Specifically, the control system 703 may process data received by such sensors and determine the position of the

end mechanisms

710, 716, 722 relative to their respective bases. In addition, because the medical tool 724 and

catheters

726, 728 may include shape and position sensors as described above, the distal end of each of the medical tool and catheters may be known relative to the end mechanism. Thus, the position and orientation of the distal ends of the medical tool and catheter relative to each other and a fixed point (e.g., one of the bases 704) within the surgical coordinate space can be determined.

Manipulator assembly 712 includes a base 704b, a moving arm assembly 709b (which includes a set of links 706b, a set of joints 708 b), and an end mechanism 716. Manipulator assembly 718 includes base 704c, motion arm assembly 709c (which includes a set of links 706c, a set of joints 708 c), and an end mechanism 722. Actuation and control of the

assemblies

712, 718 may be substantially similar to the assembly 702.

The

bases

704a, 704b, 704c can be portable such that each manipulator assembly can be individually positioned and secured as desired in an operating space near a patient. Alternatively, one or more of the manipulator assemblies may be coupled to a cart or other common platform that can be positioned in an operating space near the patient.

In the example of fig. 9, a medical tool 724 is connected to the end mechanism 710. Actuation of the control tool 724 may be controlled at least in part by the end mechanism 710 by power and control signals. The inner conduit 726 is connected to the end mechanism 716 by a connector mechanism 714. The connector mechanism 714 may be used to guide a medical tool 724 into an inner catheter 726. Actuation of the inner catheter 726 may be controlled, at least in part, by power and control signals through the end mechanism 716. The outer conduit 728 is connected to the end mechanism 722 by a connector mechanism 720. The connector mechanism 720 may be used to guide the inner conduit 726 into the outer conduit 728. Actuation of the outer conduit 728 may be controlled at least in part by the end mechanism 722 by power and control signals. The medical tool 724 is sized and shaped to fit, slide, and rotate within the inner catheter 726. In addition, the inner conduit 726 is sized and shaped to fit, slide, and rotate within the outer conduit 728. The inner conduit 726 and the outer conduit 728 may be similar to the conduit 202 described above and shown in fig. 2A. The medical tool 724 may be one of a variety of medical tools, including biopsy tools, capture probes, ablation probes, or other surgical or diagnostic tools. In alternative embodiments, one or both of the conduits may be omitted.

The three

end mechanisms

710, 716, 722 can be individually controlled to move the medical tool 724 and the

catheters

726, 728 as desired. For example, to insert the inner conduit 726 further into the outer conduit 728, the end mechanism 716 may be moved closer to the end mechanism 722. To further insert the medical tool 724 into both the inner catheter 726 and the outer catheter 728, the end mechanism 710 may be moved closer to the end mechanism 716.

The

end mechanisms

710, 716, 722 can be moved to insert the distal end of the medical tool 724 and the

conduits

726, 728 into the patient through the access port 736. As described above, tools and catheters may be inserted through natural or surgically created orifices.

A first shape restraining device 740 may be placed between the first end mechanism 710 and the second end mechanism 716. Accordingly, the first shape restraining device 740 helps to reduce bending of the medical tool 724 as the medical tool 724 is inserted into the inner catheter 726. A second shape restraint apparatus 742 is positioned between the second end mechanism 714 and the third end mechanism 722. Thus, the second shape restraining device 742 helps to reduce buckling of the inner conduit 726 as the inner conduit 726 is inserted into the outer conduit 728. Similar to the shape restraining device 308 described above, a third shape restraining device 746 is placed between the third end mechanism 720 and the access port 736. The third shape restraining device 746 helps to reduce buckling of the outer conduit 228 as the outer conduit 228 is inserted into the access port 736. The control system 703 may utilize any of the techniques described above to define the desired shape and determine whether the shape data from the medical tool 724, the inner catheter 726, or the outer catheter 728 has exceeded the defined shape. In some examples, the outer conduit 728 may serve as a shape-constraining device for the inner conduit 726, and the inner conduit 726 may serve as a shape-constraining device for the tool 724. Although flexible, the

conduits

726, 728 may be sufficiently stiff to provide support for a device extending therethrough.

One or more elements of embodiments of the invention may be implemented in software for execution on a processor of a computer system, such as control system 112. When implemented in software, the elements of an embodiment of the present invention are essentially the code segments to perform the necessary tasks. The program or code segments can be stored in a non-transitory processor-readable storage medium or device, including any medium that can store information, including optical, semiconductor, and magnetic media. Examples of processor-readable storage devices include: an electronic circuit; a semiconductor device, a semiconductor memory device, a Read Only Memory (ROM), a flash memory, an Erasable Programmable Read Only Memory (EPROM); floppy disks, CD-ROMs, optical disks, hard disks, or other memory devices. The code segments may be downloaded via computer networks such as the internet, intranets, etc.

Note that the processes and displays presented may not be inherently related to any particular computer or other apparatus. The required structure for a variety of these systems will appear as elements in the claims. In addition, embodiments are not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the invention as described herein.

While certain exemplary embodiments of the invention have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative of and not restrictive on the broad invention, and that embodiments of the invention not be limited to the specific constructions and arrangements shown and described, since various other modifications may occur to those ordinarily skilled in the art.

Claims

1. A method, comprising:

measuring a shape of a section of the elongate flexible instrument with a sensor;

comparing the measured shape of the section of the elongate flexible instrument to an expected shape; and

determining whether the measured shape of the section of the elongate flexible instrument differs from the expected shape by a predefined threshold.

2. The method of claim 1, wherein the shape of the section of the elongated flexible instrument is measured between an anatomical access channel and a proximal instrument portion.

3. The method of claim 1, wherein the section of the elongated flexible instrument extends within a shape constraining device and the desired shape is based on the shape constraining device.

4. The method of claim 3, further comprising contracting the shape-constraining device by advancing the elongate flexible instrument.

5. The method of any of claims 1 or 2-4, wherein the intended shape is an intended shape volume.

6. The method of claim 5, wherein the expected shape volume comprises one of: a substantially straight tubular volume and an arcuate tubular volume.

7. The method of any of claims 1 or 2-4, wherein the desired shape is linear.

8. The method of any of claims 1 or 2-4, wherein determining whether the measured shape of the section of the elongate flexible instrument differs from the expected shape comprises determining whether a proximal portion of the section deviates more from or along a reference axis than a distal portion of the section deviates from or along the reference axis.

9. The method of any of claims 1 or 2-4, wherein determining whether the measured shape of the segment of the elongate flexible instrument differs from the expected shape comprises determining whether a portion of the segment moves in a predefined direction.

10. The method of any of claims 1 or 2-4, wherein said measuring the shape of the section of the elongate flexible instrument comprises measuring a maximum curvature of the elongate flexible instrument.